Dry shaver having rotary inner cutter and an oscillating shear plate



9, 1966 G. STARRE 3,264,734

DRY SHAVER HAVING ROTARY INNER CUTTER AND AN OSCILLATING SHEAR PLATE Filed Jan. 24, 1964 22 3 2 I 2 [3 21 l5 l9 l8 I I I INVENTOR. GERRIT STARRE AGENT United States Patent 3,264,734 DRY SHAVER HAVING ROTARY INNER CUTTER AND AN OSCILLATING SHEAR PLATE Gerrit Starre, Drachten, Netherlands, assignor to North American Philips Company, Inc New York, N.Y., a corporation of Delaware Filed Jan. 24, 1964, Ser. No. 339,913 Claims priority, application Netherlands, Feb. 14, 1963, 289,014 2 Claims. (Cl. 30-435) The invention relates to a dry shaving apparatus comprising a set of knives, which perform, by the drive of at least one of them, a shearing motion one along the other, and having inlet apertures for the hair to be cut, in which apparatus the outer knife to be brought into contact with the skin is driven in a direction in a plane substantially parallel to the contact surface.

With such apparatus it is already known to drive the two knives so that during the movement of the shaving head in a given direction along the skin the knife being in contact with the skin moves, during part of its period of movement, with a greater speed in the direction of the shaving head along the skin than that corresponding with the speed with which the hand shifts the shaving head along the skin. This may give to some extent the advantage that during part of the periodical movement of the knife a greater number of hairs are captured in the inlet apertures and are cut off in the case in which a stationary knife is in contact with the skin. However, this has the disadvantage that during the second part of the period of movement of the knife being in contact with the skin fewer hairs are captured than by a stationary knife. This disadvantage also applies to the case in which with a round shear plate with slots having lateral hair inlet apertures not only the knife rotating beneath these slots is driven, but also an oscillatory rotary motion about the center line is given to the shear plate.

With the use of rotating toothed rim it has also been proposed to add a rotation of the set of knives as a whole in a direction of rotation opposite the direction of entering of the hairs in the slots of the shear plate, while the normal speed of rotation of the toothed rim with respect to the shear plate is maintained, so that the hairs are cut in the normal manner. Thus, it is true, the disadvantage is obviated that only during part of the additional movement a greater number and during the other part a lesser number of hairs are cut, but this solution is -only suitable for rotating knives and the drive of the knife in contact with the skin requires a comparatively high quantity of energy. The skin is, moreover stretched in the direction of rotation by friction. I

The invention has for its object to provide an improved shaving effect by an improvement in the relative movement of the shear plate in contact with the skin with respect to the skin surface and is characterized in that this movement consists of two simultaneously performed, substantially orthogonal oscillations, the frequency of one oscillation being higher than that of the other.

This provides the advantage of an improved shaving effect. Due to the rapid movement in one direction and a slow movement at right angles thereto a region of the skin is carefully scanned and each hair thereof can be captured, since the shaving slots occupy the most favourable position during the movement for capturing hairs. The disadvantage of a reduced shaving effect during part 3,264,734 Patented August 9, 1966 "ice of the movement is thus overcome. These movements are such that there is no preferential part of the movement relative to the shaving head.

An advantageous embodiment is characterized in that the radio between the frequencies of the oscillations of the outer knife is 4 to 5.

This is an advantageous ratio providing the optimum effect of the shaving head.

The invention will now be described with reference to an embodiment shown diagrammatically in the drawing, while various advantages of the present invention will become evident.

FIG. 1 is a partial sectional view of a shaving apparatus with the associated rotating knife rim and stationary stretching rim taken on the line II in FIG. 2.

FIG. 2 is a corresponding plan view on a reduced scale and FIG. 3 is a developed, diagrammatic plan view associated with FIG. 2.

For simplifying the explanation a round shear plate 1 with rotating inner cutter 2 rotating around the shaft 3 is chosen by way of example. The oscillatory movements of the shaving head are indicated by the arrows R in FIG. 2. Such oscillatory movements may also be employed, when the shear plates are formed by more or less cylindrical plates, one of which performs, for the cutting operation, a reciprocating movement in the direction of the longitudinal axis.

Apart from the driving shaft 3 for the rotary movement of the inner cutter 2, there is indicated a second driving shaft 4, the movement of which, like that of the shaft 3, can be derived from a main driving shaft 5 in any known manner. The shaft 4 has an eccentric pin 7 at its end. This pin 7 is located in a transverse slot 8 in an end piece 9, which forms part of a pivotal plate 10, which bears on a fiat part of the housing 11. The pivotal plate 10 is adapted to slide over the housing 11, but its movement is limited by a pin 12 in the housing, the end of which pin fits in a longitudinal slot 13 in the pivotal plate. The directions of the slots 8 and 13 are at right angles to each other. The pivotal plate can thus perform a movement in its longitudinal direction and to pivot around the pin 12. When the shaft 4 is driven and the pivotal plate 10 is in its normal at rest position, the pin 7 will cause the pivotal plate to perform a reciprocating movement in the longitudinal direction. With each position of the pin 7 the plate 10 is capable of pivoting about the pin 12, so that a pivotal movement can be superimposed on the reciprocating movement. To this end the shaft 4 is provided with a planetary gear 23, a planetary Wheel 14 of which is concentric to the shaft 4 and is provided with two planetary wheels 15 and 16, the teeth of which engage on the one hand a toothed wheel or sun wheel 6 on the shaft 4 and on the other hand the teeth of a toothed rim 17 of the housing 11. The planetary wheel 14 comprises a cam 18, which fits in the guide slot 19 provided in the longitudinal direction of the lower face of the end piece 9. This arrangement causes the pivotal plate 10 to perform also an oscillatory and pivotal motion, which is considerably delayed with respect to the longitudinal movement by the planetary gear.

The shear plate 1 fits slidingly in an aperture of guide member 20, rigidly secured to the pivotal plate 10. Thus the active part of the shaving head performs.

' during its linear movement, along the skin in its longitudinal direction, constantly two further motions, thus, covering a strip having a larger width than the width of i the shaving head, while due to the rapid reciprocating motion the skin is completely contacted throughout said width, all hairs being at once captured in the slots and P cut ofih Thus per unit-of time more hairs are captured and cut off and a larger region is treated than otherwise,

while there is a greater variation in the directions of the slots relative to the hairs, so that the shaving effect is further improved.

The assembly of the pivotal plate and the shear plate is journalled on the housing 11 by means of a plate 21 having a recess for accommodating the pivotal plate. This plate 21 comprises furthermore the stretching rim 22, provided on its upper face with a star-shaped grid in order to prevent the treated skin portion frombeing caught along during the oscillatory motion.

What is claimed is:

1.. A dry shaver comprising a shaving head including ing said shear plate in two directions but at different frequencies including two spaced slots, a movable: pin in one slot and a fixed pin in the other slot, the directions:

of movement of said shear plate being substantially transverse to one another in a plane parallel to the plane of shaving.

2. A dry shaver comprising a drive shaft, a shaving head having a fixed part including an apertured shear 20 an apertured shear plate and a movable cutter co-acting therewith, and means provided in said shaver for oscillat- 4x 7 plate and a movable cutter co-actingtherewith, a movable parton said fixed part of said shaving head on which said; shear plate is mounted, a first slotin said movable H part, a recess in said movable part, a first pin secured to one of said parts and engaged in said first slot whereby a reciprocating and pivotal movement is imparted relative to said fixed part,'a second slot in said movable part and .extending substantially perpendicular to said first slot, a second-pin projecting eccentrically-from one end of said drive shaft and co-acting with said second slot whereby when said drive shaft :rotates a reciprocating motion :is imparted to said movable part and a cam' rotatable by said shaft and "operatively, connected with a recess in saidmovable part when the shafttrotates, to impart an oscillatory pivotal movement to said movable part.

References Cited by the Examiner WILLIAM .FELDMAN, Primary Examiner.

MY RON C. KRUSE, Examiner. 

1. A DRY SHAVER COMPRISING A SHAVING HEAD INCLUDING AN APERTURED SHEAR PLATE AND A MOVABLE CUTTER CO-ACTING THEREWITH, AND MEANS PROVIDED IN SAID SHAVER FOR OSCILLATING SAID SHEAR PLATE IN TWO DIRECTIONS BUT AT DIFFERENT FREQUENCIES INCLUDING TWO SPACED SLOTS, A MOVABLE PIN IN ONE SLOT AND A FIXED PIN IN THE OTHER SLOT, THE DIRECTIONS OF MOVEMENT OF SAID SHEAR PLATE BEING SUBSTANTIALLY TRANSVERSE TO ONE ANOTHER IN A PLANE PARALLEL TO THE PLANE OF SHAVING. 